USA Today owner Gannett has boosted its takeover bid for Tribune Publishing Co. by about 22 percent one week after the owner of the Los Angeles Times, Chicago Tribune and other newspapers adopted a "poison pill" plan to thwart the unsolicited offer.

Gannett Co. announced Monday that it was raising its bid to $15 per Tribune share, up from the $12.25 per share it previously offered. Gannett said that the total value of the revised offer is approximately $864 million, which includes the assumption of certain Tribune liabilities, such as about $385 million in outstanding debt.

The Chicago company had rejected Gannett's prior per-share bid of $12.25, saying the price was too low.

Gannett Chairman John Jeffry Louis said in a company release that the McLean, Virginia, company was raising its offer to show its "commitment to engaging in serious and meaningful negotiations with the Tribune board to reach a mutually agreeable transaction where Gannett acquires all of Tribune."

Gannett's attempts to acquire Tribune come after a shake-up at the company. In February, Chicago investor Michael W. Ferro Jr. gave Tribune a $44.4 million cash infusion through his company Merrick Media. Ferro was later named as non-executive chairman of the newspaper publisher. Weeks later, the company ousted its CEO and named Justin Dearborn to that key job.